I try to set up collective access to EFS-folder. I want to add certificates of all users to all files in folder. Is it posible do with using powershell scripts or some another way?
There seems to be no programmatic way to do this at the moment. Windows uses cipher.exe, which can only encrypt files with the current user certificate.
This is the official article for sharing encrypted files by Microsoft. One possible workaround is to encrypt the files with a specific certificate, then export it and distribute it to every machine and user, that needs access to the files. It's a hassle, but at least it can be automated.